Device for stopping the flow of blood in extremities

ABSTRACT

A device for ligaturing parts of the body comprises a flat strap (15) of elastic material in the form of a loop (35) and a buckle attached to the latter comprising a clamping part (1) and a releasing part (2). The clamping part comprises a basic element (29) which forms a basic supporting and guiding surface (39) in the longitudinal direction of the strap (15) and has lateral faces between which the strap passes and which have locking elements ensuring a releasable connection between the clamping part (1) and the releasing party (2). The latter is connected to one end (22) of the strap, has locking elements which releasably connect it to the clamping part (1) and a clamping region (3) at the end opposite the loop (35) whose distance from the surface (39) is located in the region of the thickness of the released strap (15) when the strap buckle is assembled. When the strap buckle is assembled, the locking elements form a pivoting joint. When pressure is exerted on a front external face (18) of the releasing part (2) located between the locking elements and the buckle (35), the clamping part (3) moves away from the basic surface (39), thereby releasing the device. On the end of the clamping part (1) facing the buckle (35), a transverse rib (12) projects from the basic surface (39) towards the releasing part (2), by a distance equal to the thickness, preferably twice the thickness, of the strap. As it passes over the transverse rib, the strap (15) changes direction.

The invention pertains to a device for stopping the flow of blood inextremities as described in the characterizing part of claim 1.

In this device, which is already known from DE-OS 35 38 583, the baseruns flat as far as the forward edge of the clamping device, i.e., theedge facing the loop. The part of the strap that forms the loop is bentat the forwardmost edge of the base, forcing the strap to follow a pathalong the base. The strap is clamped farther back on the base in theclamping zone.

When the device is used, the loop is placed around an extremity, forexample, an arm, and the end of the strap is pulled through the clampingdevice until the loop surrounds the arm tightly enough. When this isdone, the loop becomes smaller, a segment of the strap is pulled intothe clamping device over the above-described forward edge, and the endof the strap extending beyond the clamping device becomes longer.However, when the loop is tightened and the strap enters the clampingdevice, the skin in contact with the inner surface of the strap ispulled along with the loop and forms a fold. As the loop is drawnfurther into the strap clamp, the fold of skin is clamped tighter andtighter, causing pain.

The objective of the invention was to improve the device of the typedescribed above in such a way that skin cannot be drawn into the strapclamp so far as to cause pain.

This objective is accomplished by the device specified in patent claim1.

The transverse rib initially raises the strap higher than is necessaryfor the strap to run into the base. It then runs down to the base and,at least in the clamping region, rests against the base. Therefore, thestrap is bent at a greater angle than in state-of-the art devices ofthis type. As a result, the skin that is drawn in by friction is behindthe transverse rib and thus no longer rests against the strap inside thestrap clamping device. The transverse rib produces separation betweenthe strap and the skin that is drawn in frictionally by the strap. Thiscould also be described as a type of separation edge. This eliminatestight squeezing of the skin and prevents pain. The skin is still drawnin by the strap, but it is no longer pulled into a constrictiontransverse to the strap, where pinching or clamping could occur.

In another design, the transverse rib has an inclined surface forsupporting the strap. The inclined surface basically follows thedirection of the entering segment of the loop. In this way, the bendingof the strap does not occur directly at the front face but rather a fewmillimeters behind it, e.g., three to five millimeters.

In another design improvement, the inclined surface is inclined at anangle of 30° to 60° to the base and preferably at an angle of 45°. Thisproduces the desired, relatively large bending angle of the strap. Theinclined surface defines the angle of entry of the strap; behind theinclined surface and the transverse rib, the strap is bent back towardsthe base in the opposite direction. In this way, there is a total bendof at least 50° (with respect to the unbent direction).

In another design improvement, the upper edge of the transverse rib isdisplaced relative to a frontal face of the clamping device that facesthe loop, and it is preferably displaced by at least the width of thestrap. This also causes the strap to bend inside the strap clampingdevice.

Additional advantages and features of the invention are described in theother claims and in the following description of a specific example ofthe invention with reference to the attached drawings. It is understoodthat this example merely serves to illustrate the invention and in noway limits it.

FIG. 1 shows a full view of a specific embodiment of the invention.

FIG. 2 is a cross section of the device shown in FIG. 1.

FIG. 3 represents a top view of the device.

FIG. 4 is a front view with the strap cut.

FIG. 5 shows a top view corresponding to FIG. 3, except that only theclamping part 1 is shown, i.e., with the release device 2 removed.

FIG. 6 shows an action diagram of the lever and the force distributionin a representation corresponding to FIG. 1.

The drawings in FIGS. 1 to 5 show the device in its tightened workingposition.

The device consists of a strap 15 that forms a loop 35 with a portion ofits total length, the clamping part 1 and the release part 2. Clampingpart 1 and release part 2 are geometrically equal parts (congruentparts) and can be fastened together by lengthwise movement (in thelongitudinal direction of the strap 15) and released in the oppositedirection. A bridge-like structure is mounted on a basically rectangularfoundation 29. This bridge-like structure consists of two congruent sidewalls 14 and a bridge part 7 connecting them. The latter part has abeveled, roof-like projecting part 10. In the extended state of thestrap 15, i.e., with the loop 35 released, the release part 2 is locatedat one end of the strap, and the clamping part 1 is located along thelength of the strap. In this position of the device, the two parts 1 and2 are displaced with respect to each other in the longitudinal directionof the strap 15. To form the loop 35 starting from this position, onepart is moved 180° around an axis lying transverse to the plane of thestrap, leading to the arrangement of parts 1 and 2 that is shown in FIG.1 to 4 and FIG. 6, in which the roof-like projection 30 the release part2 hooks under the roof-like projection 10 of clamping part 1, acting aslocking mechanisms, locking clamping part 1 and release part 2 togetherand at the same time a pivot joint is formed at this point.

If there is no tension in the loop 35, i.e., if the strap clampingdevice is not in its tightened working position, the clear opening 31 ofthe clamping zone 3 is just large enough to allow the strap 15 to bemoved in the longitudinal direction. However, as shown in FIGS. 2 and 6,as soon as a tensile stress exists in the loop 35 and as a result thefront ends of the two parts 1 and 2 that face the loop 35 are moved awayfrom each other, the tightened working position shown in the drawings isattained. This reduces the clear opening 31, causing the strap 15 to beclamped in clamping zone 3. The strap 15 passes through a chamber 11 inthe clamping part 1. The thickness of the loose end of the strap 32 isincreased by folding over and clamping (clamp 33) the strap material(overlapping 27) to prevent the strap from being pulled outinadvertently.

The strap's other end 22, which is permanently attached to the releasepart 2, is undetachably connected by wrapping it around crossbar 24 andclamping the overlapped portion 25 of the strap with a longitudinallyplaced clamp 26. The strap material is both longitudinally andtransversely elastic.

The loop 35 formed by strap 15 is placed around the extremity to becompressed. The release part 2 is hooked together with the clamping part1 by moving it longitudinally. The strap 15 is tightened by pulling thefree end 32 of the strap. This presses the clamping part 1 against thestrap in the clamping zone 3. The resulting strap tension Z increasesalong the circumference of loop 35 from the permanent attachment loop 34at the release part 2 towards the clamping part 1 (Z1, Z2, Z3), so thatthe strap 15 is secured by clamping in clamping zone 3 with the longlever arm 5 of the clamping part 1 and the common fulcrum 4 to preventits movement in the longitudinal direction.

Compression of the limb is also achieved in the strap entry region ofthe device by the projecting surfaces 17.

The strap tensile force "Z" decreases along the circumference of thelimb, so that only residual tensile force "Z1" opposes the release ofrelease part 2.

When outer surface 18 of release part 2 is lifted, the release leverlength 36 exerts a large leverage on the forward release part 2 in thedownward direction towards the clamping part 1 to terminate the clampingeffect in clamping zone 3 and allows gentle release of the compression.The process of gentle release of compression is enhanced by a deflectionof the strap on a transverse rib 12 at the front face and by theresulting strap friction.

After the strap tensile force is removed, by lightly pulling theroof-like projection 10 of the release part 2 back from the chamber 11of the clamping part 1, the release part 2 is easily separated.

In the released state of the device, the surface 18 of the release part2 and the surface 19 of the clamping part 1 form a wedge inclinedtowards the strap loop 35 to make it easier to manipulate the deviceduring removal of compression, release and separation. The increasedthickness 27 of the strap material in clamping zone 3 in the releasedstate of the device pushes the parts into the advantageous positiondescribed above.

A transverse rib 12 extending the entire width of the strap and runningat right angles to the strap is located at the forward end of thefoundation 29. The transverse rib 12 can be designed in any desired way.In the specific example shown in the drawings, the transverse rib 12 isa one-piece component of the clamping part 1, which itself otherwiseconsists of a single piece. However, it can also be an inserted,possibly rotatable axis, a number of projections arranged side by sidetransverse to the strap direction, or a similar design. The onlycritical feature is that the strap must pass over an edge, which in theexample shown in the drawings is the highest elevation of the transverserib 12. The upper, inner side of the foundation forms a base 39 thatextends practically the entire length of the foundation. The transverserib 12 projects several milimeters, for example, 2 to 3 milimeters, fromthis base 39. Expressed in slightly different terms, it projects fromthe base 39 at least the thickness of the strap and in a preferreddesign of the invention at least twice the thickness of the strap (i.e.,4 to 6 mm). Towards the front surface 17 the transverse rib 12 isbounded by an inclined surface 13 which is inclined at an angle of 45°to the base 39. The upper edge of the transverse rib is thus not in theimmediate vicinity of the front surface (which should not be expresslyexcluded), but rather is displaced inwardly (by about 5 mm in theexample shown in the drawings). The inclined surface 13 becomes arounded edge 43 towards the forward outer surface 19 of the clampingpart 1. This rounded edge is located slightly (only a few tenths of amillimeter) behind the front face 17. On the side of the strap 15 turnedaway from the clamping part 1, a free space towards the release part 2or towards the end 22 of the strap is left between the front surface 17and the upper edge of the transverse rib 12. This free space is widerthan the single width of the strap. Specifically, it does not taper likea funnel, but rather widens out behind the upper edge and as far as thebeginning of the bridgelike structure 7 of the clamping part 1, so thatskin cannot be pulled in in a funnel-like fashion in this area.

Between the transverse rib 12 and the bridge part 7 of the clamping part1 there is a slot for the passage of the strap. Behind this slot thestrap passes through a chamber 11 and comes to a position below theclamping zone 3, where it is clamped. This is the first point at whichthe strap comes into contact with the base 39.

An edge of the bridge part, which extends over the entire width of thestrap, rests against the surface of the strap that forms the innersurface of the loop. As FIG. 2 shows, this edge is positioned in such away with respect to the transverse rib 12 that the strap is bent veryslightly in the opposite direction from the direction in which the strapis bent by the transverse rib. This gives the strap a slightly S-shapedcourse. However, the bend at the edge of the bridge part 7 is muchsmaller, for example, less than 10°, while the bend at the transverserib is at least five times and preferably ten times greater.

I claim:
 1. A device for stopping a flow of blood in extremities,comprising:a flat strap made of an elastic material that forms a loop,and a strap-clamping device attached to the strap and having a clampingpart and a release part; the clamping part having a foundation thatforms a base for supporting and guiding the strap in a longitudinaldirection, and side walls, the clamping part having a first lockingmechanism for releasably fastening the clamping part and the releasepart, the strap passing between the clamping part and the release part;the release part being attached to one end of the strap, and having asecond locking mechanism for releasably fastening the clamping part,defining a clamping zone at a far end of the release part away from theloop; a distance between the clamping zone and the base in an assembledstate of the strap locking device being approximately equal to athickness of the strap when loose, whereby a clamping action is achievedbetween the base and the clamping zone; in the assembled state of thestrap-clamping device, on one hand, the first and second lockingmechanisms connecting the clamping part with the release part, and onthe other hand, the first and second locking mechanisms forming a pivotjoint; the release part having an outer surface, which is locatedbetween the first and second locking mechanisms and the loop, and when aforward part of this outer surface is pressed, the clamping zonebecoming separated from the base, thereby releasing the clamping action;a transverse rib projecting from the base at a loop end of the clampingpart by a distance at least equal to the thickness of the strap so thatthe strap runs down to the base after passing the transverse rib, thetransverse rib forming an inclined surface for supporting the strap andthe inclination of the inclined surface corresponding basically to adirection of the entering part of the loop that rests upon it.
 2. Thedevice in accordance with claim 1, wherein the inclined surface isinclined to the base at an angle of 30° to 60°.
 3. The device inaccordance with claim 1, wherein the inclined surface is inclined to thebase at an angle of about 45°.
 4. A device for stopping a flow of bloodin extremities, comprising:a flat strap made of an elastic material thatforms a loop, and a strap-clamping device attached to the strap andhaving a clamping part and a release part; the clamping part having afoundation that forms a base for supporting and guiding the strap in alongitudinal direction, and side walls, the clamping part having a firstlocking mechanism for releasably fastening the clamping part and therelease part, the strap passing between the clamping part and therelease part; the release part being attached to one end of the strap,and having a second locking mechanism for releasably fastening theclamping part, defining a clamping zone at a far end of the release partaway from the loop; a distance between the clamping zone and the base inan assembled state of the strap locking device being approximately equalto a thickness of the strap when loose, whereby a clamping action isachieved between the base and the clamping zone; in the assembled stateof the strap-clamping device, on one hand, the first and second lockingmechanisms connecting the clamping part with the release part, and onthe other hand, the first and second locking mechanisms forming a pivotjoint; the release part having an outer surface, which is locatedbetween the first and second locking mechanisms and the loop, and when aforward part of this outer surface is pressed, the clamping zonebecoming separated from the base, thereby releasing the clamping action;a transverse rib projecting from the base at a loop end of the clampingpart by a distance at least equal to the thickness of the strap so thatthe strap runs down to the base after passing the transverse rib, anupper edge of the transverse rib being inwardly displaced with respectto a front face of the clamping part facing the loop and being separatedfrom the front face by at least the width of the strap.
 5. The device inaccordance with claim 4, wherein the strap is bent at the transverse ribby at least 50°.
 6. The device in accordance with claim 5, wherein theclamping part has a bridge part connecting the side walls, an openingbeing defined between the bridge part and the transverse rib for passageof the strap, the strap being in contact with an edge of the bridgepart, and the direction of the strap being changed by a small angle atthis edge, such that this bend in the strap is in an opposite directionfrom the bend produced at the transverse rib.
 7. The device inaccordance with claim 6, wherein the small angle of bend at the edge isless than 10° in the opposite direction from the bend produced at thetransverse rib.
 8. The device in accordance with claim 4, wherein therelease part has a slot for holding a retaining loop of the strap. 9.The device in accordance with claim 4, wherein a free space is definedbetween the front face and the transverse rib on the side of the strapfacing the clamping part, this free space being at least as great as thethickness of the strap.
 10. The device in accordance with claim 9,wherein the free space between the front face and the transverse rib onthe side of the strap facing the clamping part is greater than 2 mm. 11.The device in accordance with claim 4, wherein the upper edge of thetransverse rib is inwardly displaced with respect to a front face of theclamping part facing the loop and is separated from the front face by 4to 6 mm.
 12. The device in accordance with claim 4, wherein the strap isbent at the transverse rib by at least 60°.